EP 0021866 B1 19831228 - DEVICE FOR REDUCING JAMMING SIGNALS WITH A ROTATING LINEAR POLARIZATION AND USE THEREOF IN A RADAR
Title (en)
DEVICE FOR REDUCING JAMMING SIGNALS WITH A ROTATING LINEAR POLARIZATION AND USE THEREOF IN A RADAR
Publication
Application
Priority
FR 7915139 A 19790613
Abstract (en)
[origin: US4335387A] A radar antenna of the Cassegrain type comprises a paraboloidal principal reflector confronting a hyperboloidal or flat auxiliary reflector of smaller radius directing linearly polarized radiation from a source on their common axis toward the principal reflector along lines passing through the focal point thereof to produce an axially extending outgoing beam whose central part is intercepted by the auxiliary reflector. The latter consists of an array of linear conductors generally parallel to the direction of polarization while the principal reflector is formed by another conductor array generally inclined at 45 DEG to that direction, the latter array being backed by a solid mirror separated therefrom by a distance smaller than a quarter wavelength at the midfrequency of the emitted radiation. The composite wave leaving the principal reflector has an elliptical polarization which it retains in an annular portion of the outgoing beam bypassing the auxiliary reflector; only a linearly polarized component of that wave rotated through 90 DEG from the original direction of polarization, however, passes the array of the auxiliary reflector in the central beam portion intercepted thereby.
IPC 1-7
IPC 8 full level
G01S 7/02 (2006.01); G01S 13/44 (2006.01); H01Q 19/195 (2006.01)
CPC (source: EP US)
G01S 7/025 (2013.01 - EP US); G01S 13/4409 (2013.01 - EP US); H01Q 19/195 (2013.01 - EP US)
Citation (examination)
- US 3161879 A 19641215 - HANNAN PETER W, et al
- "Les antennes", L. Thourel, page 300, Dunod 1971
Designated contracting state (EPC)
CH DE GB IT LI NL
DOCDB simple family (publication)
EP 0021866 A1 19810107; EP 0021866 B1 19831228; DE 3065980 D1 19840202; FR 2458821 A1 19810102; FR 2458821 B1 19830722; US 4335387 A 19820615
DOCDB simple family (application)
EP 80400588 A 19800429; DE 3065980 T 19800429; FR 7915139 A 19790613; US 15879480 A 19800612